Contact seals, often made of carbon and hence referred to correctly or incorrectly as carbon seals, are commonly used to provide a fluid seal around a rotating shaft, particularly high speed rotating shafts used in high temperature environments such as in gas turbine engines. Such contact seals usually comprise ring segments and a seal runner which abut and rotate relative to each other to form a rubbing, contact interface which creates a fluid seal around the shaft. Pressurized gas can be used to force the ring segments against the seal runner and create a gas pressure differential with the bearing cavity which repels impinging oil. Typically, but not necessarily, the seal runner is disposed on the rotating shaft and rotates within an outer stationary ring, causing the rubbing interface between the rotating seal runner and the rotationally-stationary ring. Although efforts are made to limit friction, the rubbing contact can generate significant heat during operation, especially in the context of high rotational speeds of gas turbine engine shafts, and means are provided to dissipate this heat. This heat dissipation is most often accomplished using fluid cooling, for example oil from the engine's recirculating oil system which is sprayed onto exposed surfaces of the seal runner and/or the ring.
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